A transmission of this type is known from the German open application No. 32 28 353, FIG. 16. It requires for eight drive speeds and eight reverse speeds a total of 23 gears, 11 gear sets and 10 synchronizing clutches. The friction clutches are separately mounted as two complete individual clutches on two different axes. Two synchronizing clutches of the main transmission are loaded not only by a shaft and the thereto rigidly connected parts of a friction clutch and two synchronizing clutches, but in addition also by four gears constituting a turning mass. The synchronizing clutches of the reverse transmission are loaded by the turning mass of two shafts, of parts of six synchronizing clutches and of a totality of ten gears.
A disadvantage of the corresponding transmission is the size of the mentioned synchronizing clutches or, if not, of their reduced lifespan.
Other disadvantages are the large number of gears and gear sets synchronous clutches, the many and long shafts and therefrom the expensive overall dimensions and weight of the transmission.